Novel N-(mercaptoacyl)peptidyl compounds of formula (I) are found to be useful inhibitors of matrix metalloendoproteinase-mediated diseases including osteoarthritis, rheumatoid arthritis, septic arthritis, tumor invasion in certain cancers, periodontal disease, corneal ulceration, proteinuria, dystrophobic epidermolysis bullosa, coronary thrombosis associated with atherosclerotic plaque rupture, and aneurysmal aortic disease. The matrix metalloendoproteinases are a family of zinc-containing proteinases including but not limited to stromelysin, collagenase, and gelatinase, that are capable of degrading the major components of articular cartilage and basement membranes. The inhibitors claimed herein may also be useful in preventing the pathological sequelae following a traumatic injury that could lead to a permanent disability. These compounds may also have utility as a means for birth control by preventing ovulation or implantation. ##STR1##
The disability observed in osteoarthritis (OA) and rheumatoid arthritis (RA) is largely due to the loss of articular cartilage. No therapeutic agent in the prior art is known to prevent the attrition of articular cartilage in these diseases.
"Disease modifying antirheumatic drugs" (DMARD), i.e., agents capable of preventing or slowing the ultimate loss of joint function in OA and RA are widely sought. Generic nonsteroidal antiinflammatory drugs (NSAIDs) may be combined with such agents to provide some relief from pain and swelling.
Stromelysin (aka. proteoglycanase, matrix metalloproteinase-3, MIMP-3, procollagenase activator, "transin"), collagenase (aka. interstitial collagenase, matrix metalloproteinase-1, MMP-1, Type II collagenase), and gelatinase (aka. type IV collagenase, matrix metalloproteinase-2, MMP-2, 72kDa-gelatinase or type V collagenase, matrix metalloproteinase-9, MMP-9, 95kDa-gelatinase) are metalloendoproteinases secreted by fibroblasts and chondrocytes, and are capable of degrading the major connective tissue components of articular cartilage or basement membranes. Elevated levels of both enzymes have been detected in joints of arthritic humans and animals: K. A. Hasty, R. A. Reife, A. H. Kang, J. M. Stuart, "The role of stromelysin in the cartilage destruction that accompanies inflammatory arthritis", Arthr. Rheum., 33,388-97 (1990); S. M. Krane, E. P. Amento, M. B. Goldring, S. R. Goldring, and M. L. Stephenson, "Modulation of matrix synthesis and degradation in joint inflammation", in The Control of Tissue Damage", A. B. Glauert (ed.), Elsevier Sci. Publ., Amsterdam, 1988, Ch. 14, pp 179-95; A. Blanckaert, B. Mazieres, Y. Eeckhout, G. Vaes, "Direct extraction and assay of collagenase from human osteoarthrtic cartilage", Clin. Chim. Acta, 185 73-80 (1989). Each enzyme is secreted from these cells as an inactive proenzyme which is subsequently activated. There is evidence that stromelysin may be the in vivo activator for collagenase and gelatinase, implying a cascade for degradative enzyme activity: A. Ho, H. Nagase, "Evidence that human rheumatoid synovial matrix metalloproteinase 3 is an endogenous activator of procollagenase", Arch Biochem Biophys., 267,211-16 (1988); G. Murphy, M. I. Crockett, P. E. Stephens, B. J. Smith, A. J. P. Docherty, "Stromelysin is an activator of procollagenase", Biochem. J., 248, 265-8 (1987); Y. Ogata, J. J. Enghild, H. Nagase, "Matrix metalloproteinase 3 (stromelysin) activates the precursor for human matrix metalloproteinase 94, J. Biol. Chem., 267, 3581-3584 (1992). Inhibiting stromelysin could limit the activation of collagenase and gelatinase as well as prevent the degradation proteoglycan.
That stromelysin inhibition may be effective in preventing articular cartilage degradation has been demonstrated in vitro by measuring the effect of matrix metalloendoproteinase inhibitors on proteoglycan release from rabbit cartilage explants: C. B. Caputo, L. A. Sygowski, S. P. Patton, D. J. Wolanin, A. Shaw, R. A. Roberts, G. DiPasquale, J. Orthopaedic Res., 6, 103-8 (1988).
There is an extensive literature on the involvement of these metalloproteinases in arthritis, but there is very little to guide one in developing a specific inhibitor for each enzyme.
In preliminary studies of rabbit proteoglycanase with substrates and inhibitors, little was found to indicate the enzyme's requirements for hydrolysis or inhibition beyond a preference for hydrophobic residues at the P.sub.1 ' position: A. Shaw, R. A. Roberts, D. J. Wolanin, "Small substrates and inhibitors of the metalloproteoglycanase of rabbit articular chondrocytes", Adv. Inflam. Res., 12, 67-79 (1988). More extensive studies with a series of substrates revealed that stromelysin will tolerate nearly every amino acid residue around the scissile bond: G. B. Fields, H. Brikedal-Hansen, H. E. Van Wart, unpublished results presented at the Matrix Metalloproteinase Conference, Sept. 1989, Sandestin Fla.
Human rheumatoid synovial collagenase has been shown to share .about.50% homology with human stromelysin: S. E. Whitham, G. Murphy, P. Angel, H. J. Rahmsdorf, B. J. Smith, A. Lyons, T. J. R. Harris, J. J. Reynolds, P. Herrlich, A .J. P. Docherty, "Comparison of human stromelysin and collagenase by cloning and sequence analysis", Biochem. J., 240,913-6 (1986). Many collagenase inhibitors have been designed around the cleavage site of the .alpha.-chain sequence of Type II collagen: W. H. Johnson, N. A. Roberts, N. Brokakoti, "Collagenase inhibitors: their design and potential therapeutic use", J. Enzyme Inhib., 2,1-22 (1987). One such inhibitor, N-[3-(benzyloxycarbonyl) amino-1-carboxy-n-propyl]-L-leucyl-O-methyl-L-tyrosine, N-methylamide, prepared at G. D. Searle, Inc., and shown to be a potent inhibitor of human rheumatoid synovial collagenase (IC.sub.50 =0.8 .mu.M), was also found to inhibit rabbit bone proteoglycanase (IC.sub.50 =0.5 .mu.M): J. M. Delaisse, Y. Eeckhout, C. Sear, A. Galloway, K. McCullagh, G. Vaes, "A new synthetic inhibitor of mammalian tissue collagenase inhibits bone resorption in culture", Biochem. Biophys. Res. Commun., 133, 483-90 (1985).
Gelatinase (MR .about.72,000) has been isolated from rheumatoid fibroblasts: Y. Okada, T. Morodomi, J. J. Enghild, K. Suzuki, A. Yasui, I. Nakanishi, G. Salvesen, H. Nagase, "Matrix metalloproteinase 2 from human rheumatoid synovial fibroblasts", Eur. J., Biochem., 194, 721-30 (1990). The synthesis of the proenzyme is not coordinately regulated with the other two metalloproteinases and its activation may also be different. The role of gelatinase in the tissue destruction of articular cartilage appears different from the other two enzymes and, therefore, its inhibition may provide additional protection from degradation. A higher molecular weight gelatinase (MR .about.95,000; aka. type-V collagenase, matrix metallo-proteinase-9, MMP-9) is also secreted by fibroblasts and monocytes and may be involved in cartilage degradation.
From the significant proportion of homology between human fibroblast collagenase, stromelysin, and gelatinase it is expected that a compound that inhibits one enzyme may have a similar effect on all of them.
Compounds that inhibit collagenase, which possess structural portions akin to those of the instant invention include those encompassed by U.S. Pat. No. 5,109,000 issued Apr. 28, 1992; U.S. Pat. No. 4,595,700, issued Jun. 17, 1986; U.S. Pat. No. 4,371,466, issued Feb. 1, 1983. Also included are compounds encompassed by claims in foreign applications EP423,943, EP273,689, EP322184, EP185,380, and WO8806890.
It is believed that stromelysin and collagenase inhibitors have utility in preventing articular cartilage damage associated with septic arthritis. Bacterial infections of the joints can elicit an inflammatory response that may then be perpetuated beyond what is needed for removal of the infective agent resulting in permanent damage to structural components. Bacterial agents have been used in animal models to elicit an arthritic response with the appearance of proteolytic activities. See J. P. Case, J. Sano, R. Lafyatis, E. F. Remmers, G. K. Kumkumian, R. L. Wilder, "Transin/stromelysin expression in the synovium of rats with experimental erosive arthritis", J. Clin Invest., 84, 1731-40 (1989); R. J. Williams, R. L. Smith, D. J. Schurman, "Septic Arthritis: Staphylococcal induction of chondrocyte proteolytic activity", Arthr. Rheum., 33, 533-41 (1990).
It is also believed that inhibitors of stromelysin, collagenase, and gelatinase will be useful to control tumor metastasis, optionally in combination with current chemotherapy and/or radiation. See L. M. Matrisian, G. T. Bowden, P. Krieg, G. Furstenberger, J. P. Briand, P. Leroy, R. Breathnach, "The mRNA coding for the secreted protease transin is expressed more abundantly in malignant than in benign tumors", Proc. Natl. Acad. Sci., U.S.A, 83, 9413-7 (1986); S. M. Wilhelm, I. E. Collier, A. Kronberger, A. Z. Eisen, B. L. Marmer, G. A. Grant, E. A. Bauer, G. I. Goldberg, "Human skin fibroblast stromelysin: structure, glycosylation, substrate specificity, and differential expression in normal and tumorigenic cells", Ibid., 84, 6725-29 (1987); Z. Werb et al., Signal transduction through the fibronectin receptor induces collagenase and stromelysin gene expression, J. Cell Biol., 109, 872-889 (1989); L. A. Liotta, C. N. Rao, S. H. Barsky, "Tumor invasion and the extracellular matrix", Lab. Invest., 49, 636-649 (1983); R. Reich, B. Stratford, K. Klein, G. R. Martin, R. A. Mueller, G. C. Fuller, "Inhibitors of collagenase IV and cell adhesion reduce the invasive activity of malignant tumor cells", in Metastasis: Ciba Foundation Symposium; Wiley, Chichester, 1988, pp. 193-210.
Secreted proteinases such as stromelysin, collagenase, and gelatinase play an important role in processes involved in the movement of cells during metastasic tumor invasion. Indeed, there is also evidence that the matrix metalloproteinases are overexpressed in certain metastatic tumor cell lines. In this context, the enzyme functions to penetrate underlying basement membranes and allow the tumor cell to escape from the site of primary tumor formation and enter circulation. After adhering to blood vessel walls, the tumor cells use these same metalloendoproteinases to pierce underlying basement membranes and penetrate other tissues, thereby leading to tumor metastasis. Inhibition of this process would prevent metastasis and improve the efficacy of current treatments with chemotherapeutics and/or radiation.
These inhibitors should also be useful for controlling periodontal diseases, such as gingivitis. Both collagenase and stromelysin activities have been isolated from fibroblasts isolated from inflammed gingiva: V. J. Uitto, R. Applegren, P. J. Robinson, "Collagenase and neutral metalloproteinase activity in extracts of inflamed human gingiva", J. Periodontal Res., 16, 417-424(1981). Enzyme levels have been correlated to the severity of gum disease: C. M. Overall, O. W. Wiebkin, J. C. Thonard, "Demonstration of tissue collagenase activity in vivo and its relationship to inflammation severity in human gingiva", J. Periodontal Res., 22, 81-88 (1987).
Proteolytic processes have also been observed in the ulceration of the cornea following alkali burns: S. I. Brown, C. A. Weller, H. E. Wasserman, "Collagenolytic activity of alkali-burned corneas", Arch. Opthalmol., 81, 370-373 (1969). Mercapto-containing peptides inhibit the collagenase isolated from alkali-burned rabbit cornea: F. R. Burns, M. S. Stack, R. D. Gray, C. A. Paterson, Invest. Opthalmol., 30, 1569-1575 (1989). Treatment of alkali-burned eyes or eyes exhibiting corneal ulceration as a result of infection with combination with sodium citrate or sodium ascorbate and/or antimicrobials may be effective in preventing developing corneal degradation.
Stromelysin has been implicated in the degradation of structural components of the glomerular basement membrane (GBM) of the kidney, the major function of which is to restrict passage of plasma proteins into the urine; W. H. Baricos, G. Murphy, Y. Zhou, H. H. Nguyen, S. V. Shah, "Degradation of glomerular basement membrane by purified mammalian metalloproteinases", Biochem. J., 254, 609-612 (1988). Proteinuria, a result of glomerular disease, is excess protein in the urine caused by increased permeability of the GBM to plasma proteins. The underlying causes of this increased GBM permeability are unknown, but proteinases including stromelysin may play an important role in glomerular diseases. Inhibition of this enzyme may alleviate the proteinurea associated with kidney malfunction.
Inhibition of stromelysin activity may prevent the rupturing of atherosclerotic plaques leading to coronary thrombosis. The tearing or rupture of atherosclerotic plaques is the most common event initiating coronary thrombosis. Destabilization and degradation of the connective tissue matrix surrounding these plaques by proteolytic enzymes or cytokines released by infiltrating inflammatory cells has been proposed as a cause of plaque fissuring. Such tearing of these plaques can cause an acute thrombolytic event as blood rapidly flows out of the blood vessel. High levels of stromelysin RNA message have been found to be localized to individual cells in atherosclerotic plaques removed from heart transplant patients at the time of surgery: A. M. Henney, P. R. Wakeley, M. J. Davies,. K. Foster, R. Hembry, G. Murphy, S. Humphries, "Localization of stromelysin gene expression in atherosclerotic plaques by in situ hybridization", Proc. Nat'l. Acad. Sci. U.S.A, 88, 8154-8158 (1991). Inhibition of stromelysin by these compounds may aid in preventing or delaying the degradation of the connective tissue matrix that stabilizes the atherosclerotic plaques, thereby preventing events leading to acute coronary thrombosis.
It is also believed that inhibitors of matrix metalloproteinases would have utility in treating degenerative aortic disease associated with thinning of the medial aortic wall. Aneurysms are often associated with atherosclerosis in this tissue. Increased levels of the degradative activities of the matrix metalloproteinases have been identified in patients with aortic aneurysms and aortic stenosis: N. Vine, J. T. Powell, "Metalloproteinases in degenerative aortic diseases", Clin. Sci., 81, 233-9 (1991). Inhibition of these enzymes may aid in preventing or delaying the degradation of aortic tissue, thus preventing events leading to acute and oftentimes fatal aortic aneurysms.
It is also believed that specific inhibitors of stromelysin and collagenase should be useful as birth control agents. There is evidence that expression of metalloendoproteinases, including stromelysin and collagenase, is observed in unfertilized eggs and zygotes and at further cleavage stages and increased at the blastocyst stage of fetal development and with endoderm differentiation: C. A. Brenner, R. R. Adler, D. A. Rappolee, R. A. Pedersen, Z. Werb, "Genes for extracellular matrix-degrading metalloproteinases and their inhibitor, TIMP, are expressed during early mammalian development", Genes & Develop., 3, 848-59 (1989). By analogy to tumor invasion, a blastocyst may express metalloproteinases in order to penetrate the extracellular matrix of the uterine wall during implantation. Inhibition of stromelysin and collagenase during these early developmental processes should presumably prevent normal embryonic development and/or implantation in the uterus. Such intervention would constitute a novel method of birth control. In addition there is evidence that collagenase is important in ovulation processes. In this example, a covering of collagen over the apical region of the follicle must be penetrated in order for the ovum to escape. Collagenase has been detected during this process and an inhibitor has been shown to be effective in preventing ovulation: J. F. Woessner, N. Morioka, C. Zhu, T. Mukaida, T. Butler, W. J. LeMaire "Connective tissue breakdown in ovulation", Steroids, 54, 491-499 (1989). There may also be a role for stromelysin activity during ovulation: C. K. L. Too, G. D. Bryant-Greenwood, F. C. Greenwood, "Relaxin increases the release of plasminogen activator, collagenase, and proteo-glycanase from rat granulosa cells in vitro", Endocrin., 115, 1043-1050 (1984).
Collagenolytic and stromelysin activity have also been observed in dystrophobic epidermolysis bullosa: A. Kronberger, K. J. Valle, A. Z. Eisen, E. A. Bauer, J. Invest. Dermatol., 79, 208-211 (1982); D. Sawamura, T. Sugawara, I. Hashimoto, L. Bruckmer-Tuderman, D. Fujimoto, Y. Okada, N. Utsumi, H. Shikata, Biochem. Biophys. Res. Commun., 174, 1003-8 (1991). Inhibition of metalloendoproteinases should limit the rapid destruction of connective components of the skin.
In addition to extracellular matrix comprising structural components, stromelysin can degrade other in vivo substrates including the inhibitor al-proteinase inhibitor and may therefore influence the activities of other proteinases such as elastase: P. G. Winyard, Z. Zhang, K. Chidwick, D. R. Blake, R. W. Cartell, G. Murphy, "Proteolytic inactivation of human al-antitrypsin by human stromelysin", FEBS Letts., 279, 1, 91-94 (1991). Inhibition of the matrix metalloendoproteinases may potentiate the antiproteinase activity of these endogenous inhibitors.